Compactors are machines used to compact initially loose materials, such as asphalt, soil, gravel, and the like, to a densified and more rigid mass or surface. For example, during construction of roadways, highways, parking lots, and the like, loose asphalt is deposited and spread over the surface to be paved. One or more compactors, which may be self-propelled machines, travel over the surface whereby the weight of the compactor compresses the asphalt to a solidified mass. The rigid, compacted asphalt has the strength to accommodate significant vehicular traffic and, in addition, provides a smooth, contoured surface that may facilitate traffic flow and direct rain and other precipitation away from the road surface. Compactors are also utilized to compact soil or recently laid concrete at construction sites and on landscaping projects to produce a densified, rigid foundation on which other structures may be built upon.
Various types of compactors are known in the art. For example, some compactors include a rotatable roller drum that may be rolled over the surface to compress the material underneath. In addition to utilizing the weight of the roller drum to provide the compressive forces that compact the material, some compactors are configured to also exert a vibratory three on the surface. As can be appreciated, the vibratory forces assist in further compacting the loose materials into a dense, uniformly rigid mass. To generate the vibratory forces, one or more weights or masses may be disposed inside the roller drum at a position off-center from the axis line around which the roller drum rotates. As the roller drum rotates, the off-center or eccentric position of the masses induce oscillatory or vibrational forces to the drum that are imparted to the surface being compacted. In some applications, the eccentrically positioned masses are arranged to rotate inside the roller drum independently of the rotation of the drum.
U.S. Pat. No. 7,213,479 discusses and shows a vibratory mechanism in which two vibratory shafts are housed within a roller drum. The two vibratory shafts are supported by and disposed between a first bulkhead and a second bulkhead of roller drum. The two vibratory shafts are driven via a drivetrain using a hydraulic motor. However, maintenance of the vibratory shafts and/or the associated drivetrain may be cumbersome and time consuming due to the location, mass, and assembly of the vibratory mechanism within the roller drum. Thus, performing even minor repairs to the vibratory mechanism could take days. This resulting down time may result in extended loss of use of the machine and increased repair labor costs.